editor / IDE setup Running a local server Onboarding Wireframing Browser dev tools Floats & how to clear them Flexbox Normal flow, positioning & z-index Namespacing & mixins Using {{dynamic}} data Conditional classes & HTML ., +, &&, ||, and ?: Handling DOM events Media queries & animations Committing, pulling, pushing, & merge conflicts encodeURIComponent() Creating new pages Communication & agile Using other preexisting UI components Creating email templates Custom modal dialogs Pull requests
persistence AJAX forms Loading states Client-side validation Server-side errors Routes & actions Querying the database Basic QA skills Server-side rendering Deploying to staging Using the REPL / db client to access the staging db DNS & registrar Reading 3rd party API docs Using Postman Making HTTP requests in server- side code SSL cert & redirects Setting environment variables Language/framework-specific configuration basics Reading 3rd party API docs Encoding request data & headers, parsing response data & headers Creating reusable helpers Negotiating errors, throwing custom errors, & using status codes
Scalability When to paginate Controlling the size of query result sets Stability Timeouts, retries & exponential backoff Most common language-specific gotchas Managing API rate limits Optimization Running things in parallel Secure file uploads Negotiating errors & throwing custom errors Reducing the # of queries and other async operations Using native queries & batch operations S3 bucket configuration Safe stream processing Listening for WebSocket messages in the browser Subscribing & broadcasting on the server PCI compliance re charging a card or enrolling a customer in subscription billing Automated SMS & emails Hashed passwords Untrusted requests Enforcing size quotas